Development images improvement proposal

[rmoch]

When developing in openedx-docker we use specifically built images.
Typical process when working on edx-platform, fun-apps or external library is to clone repository one want to work on on host filesystem, manually modify docker-compose to mount it in container, then log in container with bin/compose run --rm --service-ports lms-dev bash. Then install code, modify project settings and run Django dev server. All that ending in passing much time building images, and typing commands in a very poor container bash.

Here are some ideas to ease this process.

• Add unix packages to container like git, text editor, network related commands...
• Allow .bash_history persistence between container run
• Ease the process of mounting repositories from host to container
• install Mysql client and/or allow external connection to mysql server

The development on opendex-docker is also done by frequently changing flavors, which leads to many image builds. We could improve the situation by allowing images to be retrieved from Docker Hub instead of building them.